1. Field of the Invention
The present invention relates to a method for manufacturing an ink jet recording head for flying an ink droplet to adhere it onto a recording medium, an ink jet recording head manufactured by such a method, and a laser working method.
2. Related Background Art
In ink jet printing, print quality greatly depends upon a property of a nozzle portion for discharging, ink, and the property of the nozzle portion is determined by dispersion in nozzle diameters and shapes of nozzles. As methods for forming the nozzles, generally two methods, i.e., electrical discharge machining utilizing electroforming using a metallic plate, and, ultraviolet laser working method in which organic polymer resin material is subjected to sublimation by high energy laser such as excimer laser have been proposed. Presently, the latter method, i.e., ultraviolet laser working method has mainly been used for micro working.
In the past, when the organic polymer resin material is subjected to sublimation by the ultraviolet laser, a taper shaped working property in which worked area is gradually decreased from a laser input side to a laser output side by illuminating a laser onto the material has been achieved. By the way, in the ink jet recording head, in order to improve print quality, since a nozzle plate including nozzles tapered toward ink discharge side is required as a nozzle plate having discharge ports, when the nozzle plate is manufactured, the above-mentioned laser working method is used, and, in this case, after the nozzles are formed by illuminating the laser onto the nozzle plate from the ink supplying side, the nozzle plate is connected to an ink supplying member.
However, a length of the nozzle is required to be within a range from several tends of xcexcm to about 100 xcexcm to improve the print quality, add, thus, a thickness of the nozzle plate has the same dimension. Therefore, since the nozzle plate is very deformable and since the nozzle plate must be laser-worked from the ink supplying side as mentioned above and since the nozzle plate must be connected to the ink supplying member after nozzles were formed in the plate, after the connection, the nozzle plate is deformed by stress. Due to the stress deformation, the ink discharge nozzles which are aligned with each other in the same direction cannot be formed, with the result that ink discharging directions do not become the same, thereby deteriorating the print quality.
In order to solve such a problem, as a method for forming the ink discharge nozzles after the ink jet recording head is assembled, the following methods have been proposed.
One method is disclosed in National Publication of International Patent Application No. 6-510958. In this method, light beams regulated by mask patterns are obliquely incident on a discharge port forming plate so that the plate is worked along the light beam advancing directions due to the oblique incidence, with the result that a nozzle plate including tapered nozzles each having a wider inside width than an outside width is formed.
Another method is disclosed in Japanese Patent Publication No. 6-24874. In this method, a light beam is illuminated in a condition that a mask plate having a nozzle pattern is closely contacted with an ink discharge port forming plate. In this case, the mask plate and the ink discharge port forming plate which are closely contacted with each other are rocked or pivoted so that the light beam is obliquely incident on the plates, with the result that nozzles tapered toward outside are formed in the ink discharge port forming plate by advancing the working along the beam incident direction.
However, in the method disclosed in the National Publication of International Patent Application No. 6-510958, because of two-directional beam working, although the nozzles tapered toward outside are formed in the nozzle plate in the beam incident directions, regarding directions perpendicular to the beam incident directions, since nozzles flared toward outside are formed and cone-shaped tapers symmetrical with respect to the ink discharging direction are not formed, in the direction of the taper flared toward outside, ink discharging fluid resistance is generated to delay period of ink discharge, thereby making high speed printing impossible, and, further, in case of the flared nozzles, mist is generated during the ink discharging.
Further, also in the method disclosed in the Japanese Patent Publication No. 6-24874, since the mask plate and the ink discharge port forming plate are inclined with respect to the light beam in a time-lapse manner, in a working start condition and a working finish condition, i.e., in a time-lapse working process, it becomes difficult to form the tapers symmetrical with respect to the ink discharging direction, with the result that it is difficult to fly ink droplets stably in the given direction in the respective ink jet recording heads.
In the past, as a laser working method for micro-working a structure requiring minute construction and high accuracy, an ultraviolet laser working method has been used.
An example of such micro-working include formation of ink paths and ink discharge ports of an ink jet head.
In Japanese Patent Application Laid-Open No. 2-121842 or Japanese Patent Application Laid-Open No. 2-121845, a technique in which ink paths and ink discharge ports are formed with high accuracy by using an excimer laser which is typical as the ultraviolet laser is disclosed.
That is to say, the excimer laser is a laser in which an ultraviolet light (radiation) having short pulse (15 to 35 ns) is generated by discharge-exciting mixed gas of rare gas and halogen gas, and oscillation energy of the laser is several hundreds mJ/pulse and pulse repeating frequency is 10 to 500 Hz. When short pulse ultraviolet light having high luminance such as excimer laser light is illuminated onto a surface of polymer resin, ablative photodecomposition (APD) phenomenon in which the illuminated portion is instantaneously decomposed and scattered with plasma flash and shock noise is generated, thereby permitting so-called laser abrasion working of polymer resin.
In a YAG laser which was previously used in the laser working, although a hole can be formed, there is a disadvantage that an edge face is made rough. Further, in a CO2 laser, there is a disadvantage that craters are formed around a hole. Since such laser working is laser heat working in which working is effected by converting optical energy into thermal energy, worked configuration is apt to be destroyed and it is difficult to effect micro-working. To the contrary, in the laser abrasion working using the excimer laser, since sublimation etching is effected by photo-chemical reaction for breaking covalent bond of carbon atoms, the worked configuration is hard to be destroyed and high accurate working can be achieved.
The laser abrasion working means a method for effecting sublimation working by the laser without liquid-state condition.
Particularly in the ink jet technical field, remarkable progress is achieved by utilizing the laser abrasion working using the excimer laser.
As the laser working techniques using the excimer laser have been put to practical use, the following facts are recognized.
That is to say, the oscillation pulse time of the illumination laser is about several tends ns (nano-seconds) regarding the excimer laser as the ultraviolet laser and from about 100 pico-seconds to several ns regarding ultraviolet ray of high harmonic oscillation of YAG laser, and, it was found that optical energy of the laser light illuminated onto the workpiece is not totally used for breaking of the covalent bond of atoms.
And, by the presence of optical energy which is not used for breaking of the covalent bond of atoms, the laser-worked portion of the workpiece is scattered before it is completely decomposed, with the result that by-product is generated around the worked portion.
Further, a part of the optical energy which is not used for breaking of the covalent bond of atoms is converted into thermal energy.
Since energy density of the excimer laser is 100 mega-Watts at the maximum in the oscillation pulse, metals having high heat conductivity, ceramics, minerals (such as silicon), and quarts and glass having low light absorption are hard to be worked, and only organic resin materials can be subjected to sublimation abrasion working.
These are inevitable phenomena caused by using the excimer laser, and various techniques in which such phenomena are prevented from affecting an influence upon the actual head have been proposed.
For example, if the ink jet recording head is assembled in a condition that the by-products remain, since clogging of discharge ports will occur, a new step for removing the by-products was added.
Further, when the part of the optical energy is converted into the thermal energy, the work piece is thermally expanded during the working or partially melted, material having high glass transition point was used or working pitch was reduced.
In this way, since the above-mentioned techniques could not solve the problems completely, there were various limitations in the laser working.
On the other hand, in the above-mentioned ink jet recording head, recently, highly fine image quality has been requested. Regarding this, although arrangement density of the discharge ports and ink flow paths of 300 to 400 dpi was adequate conventionally, in recent years, arrangement density of 600 dpi or 1200 dpi has been requested.
To this end, a forming method for forming minute interval (distance) such as arrangement interval (distance) (between the discharge ports and the recording liquid flow paths) equal to or smaller than 50 xcexcm or minute configuration such as working diameter equal to or smaller than 20 xcexcm with high accuracy has been requested.
However, since the above-mentioned phenomena found in the excimer laser become remarkable as the working distance and the working diameter becomes smaller, the excimer laser has limitation in the manufacture of the highly fine head.
The inventors recognize that all of the phenomena are based on the laser abrasion working using the ultraviolet laser (such as excimer laser) and found, from new investigations apart from conception of conventional techniques, an epochal laser abrasion working technique which can eliminate such phenomena completely and cope with micro-working techniques which will be proposed in the future and improve general-purpose application.
Further, in the conventional ink jet recording heads, since the ink supply paths and the ink discharge ports cannot be interconnected smoothly and velocity vector of ink operation is directed only toward the flying direction, print quality is deteriorated.
That is to say, the ink discharge ports of the ink jet recording head applied to the ink jet recording system are formed in the plate or plate portion as cone-shaped or polygonal pyramid-shaped holes tapered toward the ink discharging direction, and the ink droplet is flown by a method in which ink liquid interface is formed on a surface of the ink discharge side by liquid surface tension obtained by making the interior of the ink discharge port hydrophilic (to the liquid ink) and giving water repelling property to the edge of the port and therearound and pressure is applied to the liquid ink by a mechanical deforming (displacement) element or a thermal bubbling element to expel the liquid ink stored in the ink jet head. Further, a method in which ink liquid interface is formed on a boundary area between the hydrophilic area and the water repelling area by giving water repelling property up to a predetermined zone within the discharge port and the ink liquid droplet is flown in the similar manner has been proposed.
However, in the conventional laser working, since three-dimensional working of the cone shape having working section changed from a second configuration to a first configuration cannot be effected, also in the ink jet recording head, the ink supply paths cannot be smoothly connected to the ink discharge ports, with the result that turbulent flows are generated in corners of the ink discharge ports at ink supply sides thereof. Consequently, error of dot placement accuracy of the ink droplets becomes great, and, since mist is generated around the ink droplets not to obtain the complete circular print dots, thereby deteriorating the print quality.
Further, in the conventional ink jet recording head, since the velocity vector of the liquid ink operation is directed only toward the flying direction, portions which are subjected to fluid resistance at the wall surfaces of the discharge nozzles are apt to be deviated from the flying direction, with the result that the error of dot placement accuracy of the ink droplets becomes great, and, since mist is generated around the ink droplets not to obtain the complete circular print dots, thereby deteriorating the print quality.
To improve this inconvenience, if the discharge nozzle can be formed as spiral or helical configuration, the ink droplet can have rotational component around the axis of the flying direction so that the ink droplet can stably flying by rotational inertia, thereby solving the above problem. However, in the conventional laser working techniques, for example, it is impossible to obtain spiral cone shape having polygonal bottom configuration connected to circular, elliptical or polygonal configuration merely by illuminating the laser beam from the excimer laser onto the workpiece.
Further, in the conventional ink jet recording heads, the ink mist remains in the ink discharge ports, which affects a bad influence upon the ink flying. That is to say, in the conventional ink jet recording heads, when the ink is flown as mentioned above, if a main droplet of the ink droplet and sub-droplet (called as satellite) following the main droplet are both flying along the symmetrical axis of the ink discharge port, high accurate print quality can be obtained. However, when the number of ink discharge operations is increased, the ink mist remains or accumulates in the ink discharge port, which affects a bad influence upon the ink flying. To avoid this, wiping means such as a wiper capable of removing such ink mist adhered to the ink discharge port is required. If the ink liquid interface formed on the ink discharge side surface is wiped by using such a wiper, the ink discharge surface edge of the ink discharge port which has an important role for determining the ink flying direction will be damaged or the water repelling film will be peeled, with the result that the performance of the ink jet recording head is worsened.
Further, the ink is normally solved in aqueous solution. If the ink jet recording head are not used for a long term, moisture is vaporized from the ink solution, with the result that the ink discharge port will be clogged due to solidification of ink. Thus, when the ink jet recording head is left as it is for a predetermined time period or more, the ink must be sucked from the ink discharge side in order to avoid the clogging of the ink discharge port.
Such an ink sucking operation leads to not only excessive ink consumption but also prevention of immediate print start. Although such a problem can be solved by capping the ink discharge ports by a cap, when the cap is closely contacted with the ink discharge port surface, bubbles are apt to be entered into the ink nozzles, and, in order to closely contact the cap with the ink discharge port surface, elastic material following the ink discharge port surface is required. To this end, although it is considered that material such as rubber or urethane is used for forming the cap, since such material is apt to be degenerated by alkali of ink, if such material is used as the cap, the material is degenerated to adhere to the ink discharge ports to change the ink flying direction.
Further, in the above-mentioned method in which ink liquid interface is formed on a boundary area between the hydrophilic area and the water repelling area by giving water repelling property up to a predetermined zone within the discharge port and the ink liquid droplet is flown in the similar manner, it is technically possible to prevent the clogging of the ink discharge ports due to solidification of ink by applying a cap to the ink discharge ports in such a manner that the cap is not contacted with the ink. However, regarding the flying direction of the ink droplet, although the ink droplet is flying along the symmetrical axis of the ink discharge port, in the satellite sub-droplet, when the ink leaves the ink discharge port, since the ink is pulled to a position where van der Waals force acts most strongly in dependence upon the flying condition at the area of the ink discharge port where the water repelling film is provided, the flying direction of the satellite sub-droplet is changed, with the result that the main droplet and the satellite sub-droplet do not fly in the same direction.
Further, since this problem depends upon the balance of delicate ink adhesion force at the water repelling surface within the ink discharge port, control thereof is difficult, and, whenever the ink is discharged, the flying direction of the satellite droplet is changed at random, with the result that, regarding the print quality, print density becomes unstable and noise such as image roughness is generated. Thus, the practical level is not reached.
If a configuration in which the cone-shaped portion flared toward the illumination side of the laser beam is connected to the cone-shaped portion flared toward the opposite direction with a symmetrical axis in common, by forming the ink liquid interface within the ink discharge port by the liquid surface tension of ink, the clogging of the ink discharge ports due to solidification of ink can be prevented by applying a cap to the ink discharge ports in such a manner that the cap is not contacted with the ink, and a discontinuous surface boundary can be formed at a boundary between the area extending toward the ink supply side (ink hydrophilic area) and the area extending toward the ink discharge side (ink repelling area), with the result that, by separating the ink flying droplet at the discontinuous surface boundary position, the main droplet and the satellite droplet of ink can always be flown along the symmetrical axis of the ink discharge port thereby to achieve high accurate printing and solve the above-mentioned problem. However, in the conventional laser working methods, for example, it is impossible to obtain the above-mentioned configuration merely by illuminating the laser light from the excimer laser onto the workpiece.
An object of the present invention is to provide an ink jet recording head manufacturing method, an ink jet recording. head manufactured by such a method, and a laser working method, which can solve the above-mentioned conventional problems, and in which a taper configuration symmetrical with respect to an axis of an ink discharging direction and totally tapered outwardly can be obtained by laser working from outside (ink discharge side) of an ink discharge port forming plate, and which can cope with highly fineness, and in which by-products are not formed and thermal energy converted during the laser working can be prevented from being accumulated on a workpiece such as resin.
Another object of the present invention is to provide an ink jet recording head manufacturing method, an ink jet recording head manufactured by such a method, and a laser working method, in which three-dimensional working of the cone shape having working section changed from a second configuration to a first configuration can be effected or spiral cone shape having polygonal bottom configuration connected to predetermined sectional configuration can be obtained or spiral cone shape having predetermined configuration connected to predetermined polygonal sectional configuration.
A further object of the present invention is to provide an ink jet recording head manufacturing method, an ink jet recording head manufactured by such a method, and a laser working method, in which a cone-shaped portion flared toward the illumination side of laser beam can be connected to a cone-shaped portion flared toward the opposite direction with a symmetrical axis in common thereby to prevent clogging of ink discharge ports due to solidification of ink, and a main droplet and a satellite droplet of ink can always be flown along a symmetrical axis of the ink discharge port thereby to achieve high accurate printing.
To achieve the above objects, the present invention provides an ink jet recording head manufacturing method, an ink jet recording head manufactured by such a method, and a laser working method, as defined by the following items (1) to (66).
(1) A method for manufacturing an ink jet recording head in which an ink discharge port for discharging an ink droplet to be adhered to a recording medium, a liquid chamber for containing ink to be supplied to the ink discharge port, an ink flow path for communicating the ink discharge port with the liquid chamber, an energy generating element provided in the ink flow path and adapted to generate energy for discharging the ink and an ink supply port for supplying the ink from exterior into the liquid chamber are formed by bonding or adhering plate members, wherein, when an orifice plate in which the ink discharge port is formed is subjected to laser working, a laser light of plural pulses having very great spatial and time energy density and emitted from a laser oscillator for oscillating the laser light at a pulse emitting time smaller than 1 pico-second is used, and the laser beam is illuminated from an outer surface side of the orifice plate which is opposite to an ink supplying side thereby to form an ink discharge port working pattern on the outer surface of the orifice plate by focus projection.
(2) A method for manufacturing an ink jet recording head according to (1), wherein a plurality of ink discharge ports are simultaneously formed at a predetermined interval by illuminating the laser light through a mask having a plurality of opening patterns formed at a predetermined pitch.
(3) A method for manufacturing an ink jet recording head in which an ink jet recording head for flying an ink droplet to be adhered to a recording medium by transmitting pressure to an ink discharge port by applying energy to ink by contacting the ink with a pressure generating source is formed by laser working, wherein, when an orifice plate in which the ink discharge port is formed is subjected to laser working, a laser light of plural pulses having very great spatial and time energy density and emitted from a laser oscillator for oscillating the laser light at a pulse emitting time smaller than 1 pico-second is used, and three-dimensional working of a cone shape having working section continuously changed from a second configuration to a first configuration is effected by illuminating a laser beam emitted from the laser oscillator onto the orifice plate under predetermined energy density and predetermined aperture number at a projection focus point of a mask pattern through the mask pattern having the second configuration different from the first configuration which is a beam section configuration at a non-focus point of the laser beam.
(4) A method for manufacturing an ink jet recording head according to (3), wherein the first configuration which is the beam section configuration at the non-focus point of the laser beam is a substantially polygonal configuration and the second configuration different from the first configuration in the mask pattern is a circular or elliptical configuration, and a cone shape in which a section configuration of the ink discharge side is a circular or elliptical configuration and a section configuration of the ink supply side is a substantially polygonal configuration is formed.
(5) A method for manufacturing an ink jet recording head according to (4), wherein the substantially polygonal configuration of the first configuration is formed by using a polygonal pupil image pattern of a projection lens.
(6) A method for manufacturing an ink jet recording head according to (4), wherein the substantially polygonal configuration of the first configuration is formed by using a polygonal stop pattern of a projection lens.
(7) A method for manufacturing an ink jet recording head according to any one of (3) to (6), wherein the section configuration of the ink supply side is formed as a substantially polygonal configuration smoothly connected to the ink supply path.
(8) A method for manufacturing an ink jet recording head according to (3), wherein the beam section configuration is a substantially polygonal configuration, and the three-dimensional working of a spiral cone shape spirally changed continuously while increasing a sectional area of a nozzle section configuration from the second configuration to the polygonal configuration is effected by illuminating the beam section configuration onto the orifice plate while rotating the beam section configuration around an optical axis, at the projection focus point of the mask pattern through the mask pattern having the second configuration.
(9) A method for manufacturing an ink jet recording head according to (8), wherein the spiral cone shape is formed as a spiral cone shape having a substantially polygonal bottom configuration gradually and smoothly twisted continuously.
(10) A method for manufacturing an ink jet recording head according to (8) or (9), wherein the spiral cone shape is worked by forming the polygonal configuration of the beam section configuration at the non-focus point of the laser beam by using the polygonal pupil image pattern of a projection lens and by rotating the pupil image pattern around the optical axis in connection with a working advancing direction of the workpiece.
(11) A method for manufacturing an ink jet recording head according to (8) or (9), wherein the spiral cone shape is worked by forming the polygonal configuration of the beam section configuration at the non-focus point of the laser beam by using the polygonal stop pattern of a projection lens and by rotating the stop pattern around the optical axis in connection with a working advancing direction of the workpiece.
(12) A method for manufacturing an ink jet recording head according to any one of (3) to (11), wherein the focus point is set at a surface side of the orifice plate directed toward the illumination side of the laser beam or at a position spaced apart from the surface side of the orifice plate directed toward the illumination side of the laser beam, whereby the three-dimensional working of the cone shape is effected.
(13) A method for manufacturing an ink jet recording head according to any one of (3) to (12), wherein, at the ink discharge port of the ink jet recording head, a water repelling film is formed in the vicinity of the ink discharge port at an ink discharge side thereof.
(14) A method for manufacturing an ink jet recording head in which an ink jet recording head for flying an ink droplet to be adhered to a recording medium by transmitting pressure to an ink discharge port by applying energy to ink by contacting the ink with a pressure generating source is formed by laser working, wherein, when an orifice plate in which the ink discharge port is formed is subjected to laser working, a laser light of plural pulses having very great spatial and time energy density and emitted from a laser oscillator for oscillating the laser light at a pulse emitting time smaller than 1 pico-second is used, and a configuration in which a cone-shaped portion flared toward the ink discharge side is connected to a cone-shaped portion flared toward the ink supply side with a symmetrical axis in common is worked by illuminating a predetermined pattern image by means of the laser beam emitted from the laser oscillator onto the orifice plate under predetermined energy density and predetermined aperture number at a projection focus point.
(15) A method for manufacturing an ink jet recording head according to (14), wherein the cone-shaped portion flared toward the ink discharge side is worked by setting the focus point at a position rearwardly of the ink discharge surface of the orifice plate, and the one-shaped portion flared toward the ink supply side is worked by setting the focus point at a portion where the cone-shaped portions are connected with the symmetrical axis in common, after the cone-shaped portion flared toward the ink discharge side is worked.
(16) A method for manufacturing an ink jet recording head according to (14) or (15), wherein a cone shape in which the cone-shaped portion flared toward the ink discharge side is greater than the one-shaped portion flared toward the ink supply side is formed.
(17) A method for manufacturing an ink jet recording head according to any one of (14) to (16), wherein the ink discharge port is formed by hydrophilic material.
(18) A method for manufacturing an ink jet recording head according to any one of (14) to (17), wherein a water repelling film is formed on a surface of the cone-shaped portion flared toward the ink discharge side and at an area in the vicinity of the ink discharge port at an ink discharge side thereof.
(19) A method for manufacturing an ink jet recording head according to (18), wherein the water repelling film is coated on the ink discharge side after the cone-shaped portion flared toward the ink discharge side is worked, and, thereafter, the one-shaped portion flared toward the ink supply side is worked.
(20) A method for manufacturing an ink jet recording head according to any one of (14) to (19), wherein the cone shape of the ink discharge port is formed in the cone-shaped portion.
(21) A method for manufacturing an ink jet recording head according to any one of (14) to (19), wherein the cone shape of the ink discharge port is formed in a polygonal pyramid portion.
(22) A method for manufacturing an ink jet recording head according to (21), wherein the polygonal pyramid portion is worked by using the laser beam having a polygonal beam section configuration.
(23) A method for manufacturing an ink jet recording head according to (22), wherein the polygonal beam section configuration of the laser beam is formed by using a polygonal pupil image pattern of the projection lens.
(24) A method for manufacturing an ink jet recording head according to (22), wherein the polygonal beam section configuration of the laser beam is formed by using a polygonal stop pattern of the projection lens.
(25) A method for manufacturing an ink jet recording head according to any one of (14) to (19), wherein the cone shape of the ink discharge port is formed in a spiral cone portion.
(26) A method for manufacturing an ink jet recording head according to (25), wherein the spiral cone portion is worked by illuminating the beam section configuration of the laser beam onto the workpiece while rotating around the optical axis.
(27) A method for manufacturing an ink jet recording head according to any one of (16) to (19), wherein the cone shape of the ink discharge port is worked in combination with the cone-shaped portion, polygonal pyramid portion or spiral cone portion.
(28) A method for manufacturing an ink jet recording head according to any one of (1) to (27), wherein the member for forming the ink discharge port is formed from resin.
(29) A method for manufacturing an ink jet recording head according to any one of (1) to (27), wherein the member for forming the ink discharge port is formed from Si or Si compound.
(30) A method for manufacturing an ink jet recording head according to any one of (1) to (27), wherein a wavelength of the laser light is within a range from 350 nm to 1000 nm.
(31) A method for manufacturing an ink jet recording head according to any one of (1) to (30), wherein a pulse emitting time of the laser light is 500 femto-seconds or less.
(32) A method for manufacturing an ink jet recording head according to any one of (1) to (31), wherein energy density of the laser beam satisfy the following relationship:
(axc3x97nxc3x97E)/t greater than 13xc3x97106 (W/cm2)
xe2x80x83where, a is absorbing rate of material of the workpiece with respect to the illumination laser wavelength, n is aperture number of an optical system for projecting the working pattern onto the workpiece at a side of the workpiece, E (unit: (J/cm2/pulse)) is energy per unit oscillation pulse time per a unit area of the laser light illuminated on the material of the workpiece, and t (unit: (sec)) is time width of the oscillation pulse of the laser.
(33) A method for manufacturing an ink jet recording head according to any one of (1) to (32), wherein the laser oscillator has a space compressing device for light propagation.
(34) A method for manufacturing an ink jet recording head according to (33), wherein the space compressing device for light propagation is constituted by chirping pulse generating means, and longitudinal mode synchronizing means utilizing a light wavelength dispersing property.
(35) An ink jet recording head in which an ink discharge port for discharging an ink droplet to be adhered to a recording medium, a liquid chamber for containing ink to be supplied to the ink discharge port, an ink flow path for communicating the ink discharge port with the liquid chamber, an energy generating element provided in the ink flow path and adapted to generate energy for discharging the ink and an ink supply port for supplying the ink from exterior into the liquid chamber are formed by bonding or adhering plate members, wherein the ink discharge port of the ink jet recording head has a tapered section configuration in which a section configuration worked by focus-projecting an ink discharge port working pattern onto an outer surface of an orifice plate which is opposite to an ink supplying side by illuminating a laser beam of plural pulses having very great spatial and time energy density and emitted from a laser oscillator for oscillating the laser beam at a pulse emitting time smaller than 1 pico-second onto the outer surface of the orifice plate is tapered toward the outer surface of the orifice plate.
(36) An ink jet recording head according to (35), wherein a plurality of ink discharge ports are formed at a predetermined interval.
(37) An ink jet recording head for flying an ink droplet to be adhered to a recording medium by transmitting pressure to an ink discharge port by applying energy to ink by contacting the ink with a pressure generating source, wherein the ink discharge port of the ink jet recording head has a cone-shaped section configuration continuously changed from a second configuration to a first configuration worked by using a laser light of plural pulses having very great spatial and time energy density and emitted from a laser oscillator for oscillating the laser light at a pulse emitting time smaller than 1 pico-second so that an orifice plate is illuminated by illuminating a laser beam emitted from the laser oscillator under predetermined energy density and predetermined aperture number at a projection focus point of a mask pattern through the mask pattern having the second configuration different from the first configuration which is a beam section configuration at a non-focus point of the laser beam.
(38) An ink jet recording head according to (37), wherein a section configuration of the ink discharge port of the ink jet recording head at an ink discharge side thereof is circular or elliptical, and a section configuration at an ink supply side thereof is substantially polygonal.
(39) An ink jet recording head according to (38), wherein the section configuration at the ink supply side is formed as a substantially polygonal configuration smoothly connected to an ink supply path.
(40) An ink jet recording head according to (37), wherein the ink discharge port of the ink jet recording head has a continuous spiral cone shape gradually twisted smoothly and in which a section configuration of the ink discharge port of the ink jet recording head at an ink discharge side thereof is circular or elliptical, and a section configuration at an ink supply side thereof is substantially polygonal.
(41) An ink jet recording head according to (40), wherein the spiral cone shape is a spiral cone shape having a substantially polygonal continuous bottom configuration gradually twisted smoothly.
(42) An ink jet recording head according to any one of (37) to (41), wherein, at the ink discharge port of the ink jet recording head, a water repelling film is formed in the vicinity of the ink discharge port at the ink discharge side thereof.
(43) An ink jet recording head for flying an ink droplet to be adhered to a recording medium by transmitting pressure to an ink discharge port by applying energy to ink by contacting the ink with a pressure generating source, wherein the ink discharge port of the ink jet recording head has a section configuration in which a cone-shaped portion flared toward an ink discharge side is connected to a cone-shaped portion flared toward an ink supply side with a symmetrical axis in common.
(44) An ink jet recording head according to (43), wherein expansion of the cone-shaped portion flared toward the ink discharge side is greater than expansion of the cone-shaped portion flared toward the ink supply side.
(45) An ink jet recording head according to (43) or (44), wherein the ink discharge port is formed from hydrophilic material.
(46) An ink jet recording head according to any one of (43) to (45), wherein a water repelling film is formed on a surface of the cone-shaped portion flared toward the ink discharge side and at an area in the vicinity of the ink discharge port at an ink discharge side thereof.
(47) An ink jet recording head according to (46), wherein the water repelling film is coated on the ink discharge side after the cone-shaped portion flared toward the ink discharge side is worked, and, thereafter, the cone-shaped portion flared toward the ink supply side is worked.
(48) An ink jet recording head according to any one of (43) to (47), wherein the cone shape of the ink discharge port is formed in the cone-shaped portion.
(49) An ink jet recording head according to any one of (43) to (47), wherein the cone shape of the ink discharge port is formed in a polygonal pyramid portion.
(50) An ink jet recording head according to any one of (43) to (47), wherein the cone shape of the ink discharge port is formed in a spiral cone-shaped portion.
(51) An ink jet recording head according to any one of (43) to (47), wherein the cone shape of the ink discharge port is combined with a cone-shaped portion, a polygonal pyramid portion or a spiral cone-shaped portion.
(52) A laser working method for effecting laser abrasion working with respect to a workpiece by illuminating a laser beam to the workpiece, wherein, when a through hole is formed in the workpiece by abrasion working, a laser light of plural pulses having very great spatial and time energy density and emitted from a laser oscillator for oscillating the laser light at a pulse emitting time smaller than 1 pico-second is used, and the laser beam is illuminated from an outer surface side of the workpiece in which the through hole is formed by the laser abrasion working, thereby working the workpiece by focus-projecting a through hole working pattern onto the outer surface of the workpiece.
(53) A laser working method according to (52), wherein a plurality of through holes are simultaneously formed at a predetermined interval by illuminating the laser light through a mask having a plurality of opening patterns formed at a predetermined pitch.
(54) A laser working method for effecting optical abrasion working by illuminating a laser beam from a laser oscillator continuously emitting light pulses having great spatial and time energy density at a pulse emitting time smaller than 1 pico-second onto a workpiece, wherein three-dimensional working of a cone shape having working section continuously changed from a second configuration to a first configuration is effected by illuminating the laser beam emitted from the laser oscillator onto the workpiece under predetermined energy density and predetermined aperture number at a projection focus point of a predetermined mask pattern through the mask pattern having the second configuration different from the first configuration which is a beam section configuration at a non-focus point of the laser beam.
(55) A laser working method according to (54), wherein the first configuration which is the beam section configuration at the non-focus point of the laser beam is formed by using a polygonal pupil image pattern of a projection lens.
(56) A laser working method according to (54), wherein the first configuration which is the beam section configuration at the non-focus point of the laser beam is formed by using a polygonal stop pattern of a projection lens.
(57) A laser working method according to (54), wherein the beam section configuration is a substantially polygonal configuration, and the three-dimensional working of a spiral cone shape spirally changed continuously while increasing a sectional area of the section configuration of the workpiece from the predetermined configuration to the polygonal configuration is effected by illuminating the beam section configuration onto the workpiece while rotating the beam section configuration around an optical axis, at the projection focus point of the mask patten through the mask pattern having the second configuration.
(58) A laser working method according to (57), wherein the spiral cone shape is formed as a spiral cone shape having a substantially polygonal bottom configuration gradually and smoothly twisted continuously.
(59) A laser working method according to (57) or (58), wherein the spiral cone shape is worked by forming the polygonal configuration of the beam section configuration at the non-focus point of the laser beam by using the polygonal pupil image pattern of the projection lens and by rotating the pupil image pattern around the optical axis in connection with a working advancing direction of the workpiece.
(60) A laser working method according to (57) or (58), wherein the spiral cone shape is worked by forming the polygonal configuration of the beam section configuration at the non-focus point of the laser beam by using the polygonal stop pattern of the projection lens and by rotating the stop pattern around the optical axis in connection with a working advancing direction of the workpiece.
(61) A laser working method according to any one of (54) to (60), wherein the focus point is set at a surface side of the workpiece directed toward the illumination side of the laser beam or at a position spaced apart from the surface side of the workpiece directed toward the illumination side of the laser beam, whereby the three-dimensional working of the cone shape is effected.
(62) A laser working method according to any one of (52) to (61),wherein a wavelength of the laser light is within a range from 350 nm to 1000 nm.
(63) A laser working method according to any one of (52) to (62), wherein a pulse emitting time of the laser light is 500 femto-seconds or less.
(64) A laser working method according to any one of (52) to (63), wherein the workpiece is formed from Si or Si compound.
(65) A laser working method according to any one of (52) to (64), wherein the laser oscillator has a space compressing device for light propagation.
(66) A laser working method according to (65), wherein the space compressing device for light propagation is constituted by chirping pulse generating means, and longitudinal mode synchronizing means utilizing a light wavelength dispersing property.